Air conditioning plant



Jan. 30, 1940. R. H. FOLSOM AIR CONDITIONING PLANT 2 Sheets-Sheet 1 Filed April 25, 1938 1 N VENT OR.

Jan. 30, 1940- R. H. FoLsoM 2,138,811

AIR CONDITIONING PLANT I Filed April 25, 1938 2 Sheets-Sheet 2 INVENTOR.

0 0 4 m 0 4 yr m w 7.. 8 W 1 4 r a I l 1 Patented 30, 1940 UNITED STATES PATENT OFFICE 2,1aas11 1 AIR CONDITIONING PLANT Robert H. Folsom, Los Angeles, Calif. Application April 25, 1938. Serial No. 204,043

4 Claims.

My invention relates to air conditioning and refrigeration-heating, particularly where a re-.

frigerant is evaporated in thermal contact with outdoor air and is compressed and then condensed in thermal contact with indoor air.

The primary object of the invention is an efl'icient, low-cost and compact unit embodying an air-cooling evaporator coil, an air-heating condenser coil, together with such air-moving and controls as will provide for efficient heating, cooling, and moisture control thruout all seasons of the year, merely by connecting the unit with a common refrigeration compressor of suitable capacity.

Easy change from heatlnglto cooling and vice versa, are among the objects of the invention. and a particularly important object is to provide for easily and economically defrosting the evaporator coil whenever required.

Another object is to provide for moving lesser amounts of air over the condenser when it is serving as the means for heating indoor air, and

greater amounts of air over same when it is serving as a condenser in warm weather. Likewise with the evaporator it is an object to move relatively large amounts of cold atmospheric air over same to absorb heat with the minimum temperature differential, but to limit the amount of air moved in the cooling season in order to provide combined cooling and dehumidification.

- A constant supply of outside or atmospheric air to the conditioned space is another object of the invention as is also the reduction of certain thermodynamic losses common to the usual refrigeration cycle.

Ease of installation in old buildings is another object of the invention as is also the provision of a unit which in smallsizes maybe provided as a ductless local unit but which in large sizes can be used as a central air conditioning plant.

Still another object of the invention is the provision of means whereby air heating may be carried on simultaneously with air dehumidification so that dew points may be controlled in damp weather when cooling would be objectionable.

Other objects and advantages will appear hereinafter and include low cost mass production and a unit which a high percentage of home owners can afford so that more electricity will be used for heating purposes with consequent conserva-.

tion of natural fuels.

I have'illustrated by the accompanying drawings one useful embodiment of my invention. In the drawings:

passing thru the partition I5.

Figure 1 is a vertical mid-section of said em-- bodlment. I,

Figure 2 isa fragmentary section seen on line 2-2 of Fig. 1.

Figure 3 is a face view of the unit seen from 6 out-of-doors.

Figure 4 is a section seen-on lined-4 of Fig. 3; this view showing the unit installed in a building wall.

Figure 5 is a plan view of the unit.

The condenser, of the usual fin-and-tube type is indicated at I0 and the evaporator is indicated at l I; both being here shown as positioned one above the otherin the same vertical plane and mounted in a frame I 2 common to both. Between them frame l2 provides a space M, which by a vertical partition i5 is divided respectively into an outdoor chamber I6 and an indoor chamber 11. "In the space is a fresh air duct 18 open at each end to the corresponding chamber and 20 In the duct l8 there is provided an elongated fin-andtube coil 20 hereinafter known as the fresh air coil.

The condenser begins with a compressed vapor manifold 2| to receive compressed vapor from a any suitable compressor (not shown), and terminates in a. liquid manifold 22 to which there is connected the usual receiver 23. The evaporator is provided with the usual manifold 24 to dis-- tribute partially expanded liquid to the coils, and N terminates in the usual suction manifold 25 thru which vapor is drawn oil. by the said compressor.

Coil 20 begins with the manifold 26 and ends with themanifold 21. The line 28 which connects the receiver 23 with the condenser is fitted 38 with a common expansion valve 30 and this valve 30 connects with the manifold 26 of coil 20. A second and similar expansion valve 3| connects the manifold 21 of coil 20 with a line 3| leading to the manifold 24 of the evaporator. Around 4. each expansion valve there is provided a valvecontrolled by-pass such as 32 so that either expansion valve may be rendered inoperative as such by opening the corresponding by-pass. When expansion valve Sills by-passed the coil 20 g becomes substantially a. part of the liquid receivpassed coil 20 becomes a part of the evaporator.

The frame and assembly of coils provides a complete self-contained unit which connected with a compressor provides a complete refri'gerant cycle which should be manufactured and tested all in the factory and charged with an amount of liquid refrigerant suiiicient to 1111 coil jects forwardly and rearwardly of the parts about to be described. The space H is closed at each side of the frame by side walls 35 and 36 respectively. The side wall 35 is provided with fresh air inlets 31 which open to the-fresh air outdoor chamber |6 of space l4, while the side wall 36 is-provided with fresh air outlets 38. leading from the indoor chamber l1 of space l4.

Air is supplied to the coils as required, and directed away from the coils as required, by a pair of damper-box units 40 and 4| respectively;

' which units by reason of their design and function should more correctly be known as fourway" valves, and which are so termed hereinafter.

The four-way-valve 40 is known as the inlet valve and is provided respectively with an indoor air inlet opening 42 at the front thereof and centrally thereof, and with anoutdoor air inlet open-. ing 43 at the rear thereof and directly opposed to opening 42. At the upper end the valve 40 terminates in an outlet branch 44 which alines directly with the condenser, and at the lower end this valve terminates in a branch 45 whichalines with the corresponding side. of the evaporator.

The fourway-valve 4| is Qmilar to valve 40 and is placed on the opposite side of the frame but its front and rear openings 46 and" serve respectively as the out-.doorair o'utlet(46) and the indoor air outlet (41); and 49 respectively are branch 49 leading from the evaporator.

It will be apparent that thj' four-wayevalves function in the customary manner ini'that in the inlet may be in commuvided for moving two streams of air; one into the outdoor inlet of valve 40 and one into the indoor inlet of valve .40, and in the present form of the invention such means is shown in the form of an indoor air fan and an outdoor air fan 52; fan 5| being in the indoor outlet of valve 40 and fan 52 being in the outdoor outlet of the same valve. This provides that the fans are opposite and coaxial and may both be driven by a single motor 53.

While the complete unit including the coil frame and the abutting valves and may be variously installed, the drawings show the unit as fitted directly in the wall 54 .of a build-.

ing with the indoor side projecting into the building and with the outdoorside projecting out-of-doors.

The diagonal movable member or plug common to usual four-way valves is indicated for each ofthese valves by the numerals 56, 51 and 58 respectively; each member being in three parts and in the form of what may be termed a butterfly and comprising a body 56 andtwo wings 51 and 58 respectively. The motor 53, in this embodiment is supported in the corresponding particularly, the frame prorator at rates varying with the then existing dewhile itsbranches 48 j knownas inlets, the branch 4|! leading from the condense and the body a. The indoor fan It being smaller and of.

le'ssair moving capacity than the outdoor fan 52, the coils at any time subject to outdoor air receive more air than do the coils then subject to indoor air; this in keeping with a feature of 5 the invention. The outdoor inlets 31 of space l4 and provided in wall 35 are arranged or positioned so that they are always in direct communication with the out-o'f-doors. Via the fan 5| outdoor air, in continuous but moderate amount is drawn in thru inlets 51. Outlets 35 are positioned so that they are always in communication with the indoors via the fan 5| so that this supply of fresh air, afterpassing over coil 20 is discharged indoors along with the recirculated air' normally handled by the fan 5|. Each of the said wings of each valve are movable from full line position to broken line position altho m the embodiment shown herein both of the upper. wings 51 are connected to a shaft 51 while the lower wings 55 are connected to a shaft 58a. These shafts extend entirely thru the unit and terminate in'knobs 50 so that the shafts may be turned independently to set the wings as required. It will be understood that while hereinafter the wings are described as manually operated they may be controlled for air conditioning, defrosting, reheating and like operations by suitable automatic devices such as are well understood in the art. with any suitable compressor operating to sup-v ply compressed vapor to the condenser and to withdraw low pressure vapor from the evapomand, operation is as follows:--The fans are I operated continuously when any air conditioning "is-required and in heating reason the wings are all set in full line position as shown particularly in Fig. 4. With reference to Figs. 3, 4 and 5 particularly, indoor fan 5| now acts to draw indoor air in thru inlet 52, up into branch 44 of damper-box 40, over the condenser coil l0 into branch 48 of damper-box 4| and then down to and thru outlet 41, from-where the fan 5| moves. the now heated air back into the room. Frame l2 tends to separate air leaving outlet 41 from mixing with air entering inlet 42. 1

Meanwhile the outdoor fan 52 draws atmospheric air in thru inlet 45, down into branch 45 of damper-box 40, over the evaporator coil into branch 45 of damper-box 4|, and then up to and thru outlet 45. From' outlet 46 this refrigerated air, which has given up heat to generate vapor in the evaporator II, is discharged back to the atmosphere in a stream which. by frame I2, is kept separate from the air then entering inlet 45.

- At times during this method for extracting low temperature heat from outdoor'air and delivering it as useful heat to indoor air, frost will form on coil II and tend to reduce the eiilciency' of same and retard flow of air. This will cause the fan 52 to show increasing suction or reboth evaporator and condenser and can only churn air. Meanwhile fan 5| is free to draw 1 some air from inlet 42 up into branch 44, over the condenser coil l0, into branch 48 and down to and thru outlet 41, However this fan will also act to move an equal amount of indoor air from inlet 42, down into branch 45, over the evaporator into branch 49 and then up to and thru outlet 41 where the cooled air which has just passed over the evaporator is mixed with the warmed air which has just passed over the condenser. The warm room air passing over the evaporator will melt the frost therefrom and dry the coil surfaces and defrosting is thereby quickly accomplished while the mixture which the fan 5| then discharges to the room is not cold or objectionable. For cooling" as in summer weather both shafts 51a and 58a are moved anti-clockwise (Fig. 4) to dispose wings 5'! and wingsin broken line position where they bring the outdoor openings 43 and 46 respectively into communication with the condenser II and bring the indoor openings 42 and 41 in communication with the evaporator. Now fan 5| draws indoor air in thru inlet 42, down in to branch 45 of damper-box 40, over the evaporator coil into branch 49 of damper-- box 4|, and then up to and thru the indoor outlet 41 back to the room. Thus indoor air is circulated and cooled. Meanwhile fan 52 is drawing outdoor air in thru inlet 43, up into branch 44 of box 40, over the condenser coil Ill into branch 48 of box 4| and then down to and thru outlet 46 back to the atmosphere. Thus atmospheric air is moved over the condenser.

There will be times in mild but humid summer weather and in damp but not very cold spring and fall weather, when it is advantageous for comfort, health, and protection of interior furnishings, to lower the indoor dew point. This is done by having the damper wings in the same position as that just described for defrosting. Then some indoor air is moved over the evaporator and due to the reduced amount of air the evaporator will materially lower its temperature and dew point. At the same time some indoor air is heated by passing over the condenser but the admixture of cooled air and heated air which is discharged by fan 5| into the room will not appreciably heat the room. If even this amount of heat is. too much the upper wings 51 may be moved to a suitable intermediate position so that fan 52 will move a small amount of outdoor air in thru inlet 43, over the condenser and then thru outlet 46 back to the atmosphere so that some heat is thrown out-of-doors while other heat of the condenser heats some recirculating indoor air to fully or partially offset the cooling effect of air which has been moved over the evaporator for dehumidiflcation.

It will be apparent now that the unit provides heat and cold on tap and provides for distributing both thermal efi'ects in various proportions as required between indoor air and outdoor air; thus meeting all possible air-conditioning requirements for the year.

.In Figures 1 and 4 it is seen that openings 31 and 38 respectively are always on opposite sides of the dampers, for all damper positions. In other words the opening 31 is virtually out-ofdoors at all times While the opening 38 is at all times indoors but subject to the suction effect of fan 5|. Thus no matter what may be the position of the damper wings the indoor fan 5| acts to draw outdoor air thru inlet 43, then thru opening 3! (see Fig. 1) then into chamber l6, then thru duct l8 over coils 20 into chamber ll,

and then (see Fig. 4) from chamber I'I thru opening 38 to indoor air inlet 41. Thus while this will be a small amount of air as compared with that additionally moved by fan 5|, it will provide a constant flow of ventilating air from gait-01410015 to indoors over the pre-heating coil When the outdoor air is below required indoor temperature by-pass valve 32 is opened and bypass valve 32 around the expansion valve 3| is closed so that the expansion valve 3| serves only the evaporator coil ll. This causes the coil 2|! to pass condensate from the condenser I counter-current to the fresh ventilating air moving thru duct 8, and the fresh air is thereby heated while the condensate is cooled so that by the time it reaches expansion valve 3| it contains little heat above evaporator temperature and expansion valve heat loss is reduced to a practical minimum. 1

When the outside air supplied thru dust I8 is to be cooled and particularly dehumidifled the by-pass around expansion valve 3| is opened and the by-pass around expansion valve 30 is closed so that expansion begins in coil 20 and this coil becomes a part of the evaporator. Due to the relatively great depth of this coil along the line of air flow and due to the moderate amount of air moved over it, the incoming fresh air is very materially dehumidified in summer weather. While this dehumidifled air will be objectionably cold in summer and might otherwise'be too heavy,-it mixes with recirculating indoor air as it issues from opening 38 and passes to. the fan Generally speaking, this invention provides both heat and cold" on tap at all times and in varying combinations and makes practically all forms of air conditioning possible both for human comfort as well as for industrial purposes. In the foregoing I have been specific as to construction, arrangement of parts, method and conditions of operation, etc., etc., but only by way of example and explanation and not by way of I imposing limitations to the broad scope of the air selectively over same, a condenser, means for moving either indoor air or outdoor air selectively over same, a coil connecting said condenser with said evaporator, means for moving outdoor air continuously over said coil, an expansion valve between said condenser and said coil, a second expansion valve between said coil and said evaporator, a by-pass valve around the first named expansion valve adapted to be opened when outdoor air is moved over said evaporator and indoor air is moving over said condenser and to be closed when indoor air is moving over said evaporator and outdoor air is moving over said condenser, and a second by-pass valve around the second named expansion valve to be opened when open.

3. In an air conditioning plant a condenser lets and the evaporator being disposed across the other of said outlets. a second damper boxhaving an indoor outlet in the front thereof, an

outdoor outlet in the rear thereof, and a pair of spaced inlets in the side thereof one directly at the evaporator and the other directly at the condenser, means for moving air from said indoor inlet to said indoor outlet, means for moving air from said outdoor inlet to said outdoor outlet, and dampers in said boxes movable to any preselected of three positions in one of which the first named means acts to move air over the condenser while the second named means moves air over the ecaporator, and in the second of which positions the first named means moves air over the evaporator while the second named= means moves air over the condenser, and'in the third of which positions the second named means is rendered inoperative while the first named eans moves air over the condenser and evaporator simultaneously.

4. The air conditioning plant evaporator, and a fresh air duct for said last named coil having one end opening into a damper box adjacent-the indoor outlet and the other end opening into a damper box adjacent an outdoor inlet; one of said air moving means operating in all positions of said dampers to move outdoor air continuously thru said duct.

ROBERT H. FOLSOM.

"as in claim 3 and further including an air-heating-liquid-cool- -ing coil connecting said condenser with said '1 

